Foaming cosmetic compositions must satisfy a number of criteria including cleansing power, foaming properties and mildness/low irritancy with respect to the skin, hair and the occular mucosae.
Skin is made up of several layers of cells which coat and protect the keratin and collagen fibrous proteins that form the skeleton of its structure. The outermost of these layers, referred to as the stratum corneum, is known to be composed of 250 A diameter protein bundles surrounded by 80 A thick bilayers of epidermal lipids and water. Anionic surfactants can penetrate the stratum corneum membrane and, by delipidization (i.e. removal of the lipids from the stratum corneum), destroy its integrity. This destruction of the stratum corneum bilayers can lead to dry rough skin and may eventually permit the surfactant to interact with the viable epidermis, creating irritation.
Ideal cosmetic cleansers should cleanse the skin or hair gently, causing little or no irritation without defatting and or drying the skin and without leaving skin taut after frequent use. Most lathering soaps, liquids and bars fail in this respect.
Certain synthetic surfactants are known to be mild. However, a major drawback of most mild synthetic surfactant systems, when formulated for skin cleansing, is poor lather performance compared to the highest bar soap standards (bars which are rich in coconut soap and supernatted). On the other hand, the use of known high sudsing anionic surfactants with lather boosters can yield acceptable lather volume and quality. Unfortunately, however, the highest sudsing anionic surfactants are, in fact, poor in clinical skin mildness. Surfactants that are among the mildest, such as sodium lauryl glyceryl ether sulfonate, (AGS), are marginal in lather. These two facts make the balancing of the surfactant selection and the lather and skin feel benefit a delicate process.
Rather stringent requirements for cosmetic cleansers limit the choice of surface-active agents, and final formulations represent some degree of compromise. Mildness is often obtained at the expense of effective cleansing, or lathering may be sacrificed for either mildness, product stability, or both.
Thus a need exists for foaming cosmetic compositions which will produce a foam which is abundant, stable and of high quality (compactness), which are effective skin and hair cleansers and which are very mild to the skin, hair and occular mucosae.
It has been found that the use of specific polyol alkoxy esters in combination with specific amphoteric surfactants provide cosmetic cleansing compositions with significantly improved dermal mildness benefits and also good physical characteristics such as foaming.
It is therefore an object of the present invention to provide an improved cosmetic cleansing composition which thoroughly cleanses the skin and hair and which is very mild to the skin, hair and occular mucosae.
It is a further object of the present invention to provide an improved cosmetic cleansing composition which is mild and which will produce a foam which is abundant, stable and of high quality, and which effectively cleans skin and hair.